This disclosure relates to gas turbine engines, and more particularly to an apparatus, system and method for progressive stall recovery in a gas turbine engine.
Over the course of an operating cycle of a gas turbine engine, a compressor section of the engine may experience compressor stall. Compressor stall is a limiting factor in the operation of gas turbine engines. In modern gas turbine engines, unstable flow may develop in the compressor during acceleration phases and/or under high altitude and lower speed flight conditions. Such unstable flow may lead to stall, which may increase turbine temperature, mechanical vibration, reduced cooling air supplied to the turbine, loss of thrust control, or other undesirable engine operation.
During an engine stall, a pilot-requested action or a control may automatically attempt to recover engine stability and then accelerate back to a power setting commanded by the pilot. Re-acceleration is typically required to be complete within a predetermined time period as part of engine certification. For a healthy engine which has encountered a temporary disturbance, meeting re-acceleration requirements after a stall is usually not a problem. However, for a heavily degraded or damaged engine, re-acceleration may not be possible within the time constraints that typically define control schedules.
Accordingly, it is desirable to provide a method and/or apparatus for improving stall recovery in a gas turbine engine.